Historical weather data, all-time temperature records, and monthly climate averages for Troy, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Troy lands right in that classic spring swing — expect a high near 63° and a low around 40°, but the date has seen everything from 88° warmth in 1988 to a bitter 24° in 1970. There's about a 1-in-3 chance of rain, so keep an umbrella handy, but snow is nearly a non-issue at just 1%.
Troy's weather history is not for the faint of heart — this southwest Illinois town has baked at 110° in July 1954 and frozen at -27° in January 1977, a swing of 137 degrees. A single June day in 1957 dropped 8.15 inches of rain, and January 1982 buried the area under 14.8 inches of snow in one storm.
Troy peaks in heat during the third week of July, when average highs touch 90°, and bottoms out in mid-January with highs barely reaching 39°. The wettest stretch is late June, so summer travelers should pack accordingly. Spring and fall offer the most comfortable windows, with October highs averaging a pleasant 71°.